53 cam for auto

C

cjs1958

New member
I just started working on a 53 Sunliner (heavy) with a Fordomatic. I'm going for a .020 overbore on original flathead. I'm rebuilding the motor to appear all stock, but would like to bump HP with a better cam if possible. My stock cam is bad. The fella helping me with the motor says if I go with a performance cam, my automatic won't shift right. Anybody have any thoughts or experience with this. Any suggestions for cam, or someone to regrind mine? Thanks.
 
Unless you make a lot of other modifications to the engine, just about any aftermarket cam will reduce performance. The later stock cams are about as good as they come for this application IMO. One thing that will really help is uping the compression ratio by reducing the clearance between the piston and the head to around .050. If you can not locate a good original cam, there are several cam grinders here on the Barn that should be able to grind you one.

And welcome to the Barn!
 
I was considering putting an Isky Max-1 cam in the '51 Merc that went into my '51 coupe (also a relatively heavy car), and after much research and discussion, stayed with the stock Merc cam. Also, I am a real fan of an 1/8" overbore on these engines. This will yield 258 ci, 3 more than the vaunted 4" Mercury crankshaft. I figure that if the Ford engineers considered the expensive option of an entirely new crankshaft and pistons was justified because of the increased weight of the Mercury's, why not take the much cheaper (if not free) option of a safe overbore? Just about all of these engines will go out to 3 3/8" with no problem, so 1/8" leaves room for further corrections. If you need new pistons anyway, why not go the extra for about the same piston cost?
 
I also agree with "JSeery" about optimizing the "squish" between the piston crown and head. On the first couple of engines I built (pre "Ford barn"), I just threw on a set of "Hi-Compression" heads without checking and was always slightly disappointed with their performance. (I have less confidence about the manufacturers holding tolerances than I was then.) On the last two, I have spent quite a bit of time optimizing the piston/head clearance and have been much more satisfied with the results.

A small base Rochester carburetor on a bored out Mercury manifold results in a nice street engine with a notable increase in power without busting your budget.
 
Hi Denny ,
I am planning on taking your advice on the carb and manifold combo .
I was just going to ask you what carb you used,,,,and exactly what size you bored the intake to .
I’m leaning towards keeping my stock Mercury intake after all .

Tommy
 
cjs1958 said:
I just started working on a 53 Sunliner (heavy) with a Fordomatic. The fella helping me with the motor says if I go with a performance cam, my automatic won't shift right. Anybody have any thoughts or experience with this. Any suggestions for cam, or someone to regrind mine? Thanks.
Click to expand...
The only issue I can visualize using a performance cam with the FordOmatic is if using one requires a higher idle speed.
The FordOmatic is generally set to 500 RPM or less.
Get a good stock Ford or Mercury cam.
 
I’m still gathering parts but I got a Canadian aluminum four bolt intake and a 1956? Rochester 2gc carb.


Sent from my iPhone using Tapatalk
 
Thanks for the info. Is the Merc cam more lift or duration or both? How can I find the guys on the barn to get cams from? I see a swap area, is that where I should be looking? I've been doing a lot of reading and I was planning on going with .050 clearance on heads. I would like to build a hotter motor but I think this car needs to stay close to stock. Thanks Guys I appreciate the information.
 

Attachments

  • Cam specs.jpg
    Cam specs.jpg
    63.6 KB · Views: 64
Grease348 said:
I’m still gathering parts but I got a Canadian aluminum four bolt intake and a 1956? Rochester 2gc carb.


Sent from my iPhone using Tapatalk
Click to expand...

I have this same setup on my '51 and it works very well. I used a Rota-Broach in my drill press to bore the manifold to 1 7/16" to match the Rochester carb. The increase in the area of the throttle bores is in the neighborhood of 30%. It's even greater when replacing a Ford 3 bolt carburetor.

If you would like to see it, I could send you a copy of the PM I am sending to Tommy.
 
I have a cam that has cast "1cm" on it--is it the same as an 8cm? Was in a block with 8cm heads and 4" crank, rotators valves. Searched and can't find anything about it.
 
I would deffinately bore to 3 5/16. this will at aprox 20 ci and a poiin compression. Best cam would be a 52/53 EAB stock cam, which was made for the auto.
Gramps
 
tubman said:
I have this same setup on my '51 and it works very well. I used a Rota-Broach in my drill press to bore the manifold to 1 7/16" to match the Rochester carb. The increase in the area of the throttle bores is in the neighborhood of 30%. It's even greater when replacing a Ford 3 bolt carburetor.

If you would like to see it, I could send you a copy of the PM I am sending to Tommy.
Click to expand...
Yes I'd like to see it
 
swedishsteel said:
I have a cam that has cast "1cm" on it--is it the same as an 8cm? Was in a block with 8cm heads and 4" crank, rotators valves. Searched and can't find anything about it.
Click to expand...

"1CM" was the designation used on new for 1951 parts. I don't know much more than that, but I would guess that Ford engineers may have changed the profile a bit to accommodate the new for 1951 Merc-o-Matic transmission. If I had to guess, I would say that it would be a little milder than an "8CM" because of the idle requirements of the automatic transmissions.

I am now aware of 4 distinctly different 8BA type cams : (8BA, 8CM, 1CM, and EAB). There may be more. It sure would be nice if someone could find the definitive specifications for these (and any others). It would be an interesting comparison.
 
As per JDL 08-10-2010.
Cam Specs.

Default Re: 53 Mercury camshaft
49-51 ford "B" cam
.305 lift
int. opens 5*btc - closes44*abc set.017
exh. opens 48*bbc -closes3*atc set.019

52-53 ford "E" EAB cam
.328 lift
int. opens 21*btc - closes68*abc set.017
exh. opens 56*bbc - closes11*atc set.019

49-50 merc "8CM" cam
.338 lift
int. opens 10*btc - closes50*abc set.014
exh. opens 50*bbc - closes10*atc set.016

51-53 merc "1CM" cam
.333 lift
int. opens 5*btc - closes51* abc set.017
exh. opens 47*bbc - closes9* atc set.019

I used the above as a reference along with Tilden Specs.
I settled upon a NOS 1CM cam for a stroker engine 285cu".

Phil NZ
 
Thanks Phil, that's good information. It looks like the 1CM was detuned slightly from the 8CM as I guessed. One minor question; did the '52-'53 mercury's use the 1CM cam or was there a separate "EAC" cam for them? Also, is there such a thing as an "8RT" cam?

Looks like the 8CM is the "best" stock for cam given the information we have (the highest lift, at least).
 
You must log in or register to reply here.
Back
Top